linux-kernel - [PATCH] usb:xhci fix panic in xhci_free_virt_devices_depth

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 6 Nov 2017 11:28:55 +0800
From:   Yu Chen <chenyu56@...wei.com>
To:     <mathias.nyman@...el.com>, <gregkh@...uxfoundation.org>,
        <linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC:     <fanning4@...ilicon.com>, <lirui39@...ilicon.com>,
        <yangdi10@...ilicon.com>, <wangbinghui@...ilicon.com>,
        <groeck@...gle.com>, <john.stultz@...aro.org>
Subject: [PATCH] usb:xhci fix panic in xhci_free_virt_devices_depth_first

From: Yu Chen <chenyu56@...wei.com>

Check vdev->real_port 0 to avoid panic
[    9.261347] [<ffffff800884a390>] xhci_free_virt_devices_depth_first+0x58/0x108
[    9.261352] [<ffffff800884a814>] xhci_mem_cleanup+0x1bc/0x570
[    9.261355] [<ffffff8008842de8>] xhci_stop+0x140/0x1c8
[    9.261365] [<ffffff80087ed304>] usb_remove_hcd+0xfc/0x1d0
[    9.261369] [<ffffff80088551c4>] xhci_plat_remove+0x6c/0xa8
[    9.261377] [<ffffff80086e928c>] platform_drv_remove+0x2c/0x70
[    9.261384] [<ffffff80086e6ea0>] __device_release_driver+0x80/0x108
[    9.261387] [<ffffff80086e7a1c>] device_release_driver+0x2c/0x40
[    9.261392] [<ffffff80086e5f28>] bus_remove_device+0xe0/0x120
[    9.261396] [<ffffff80086e2e34>] device_del+0x114/0x210
[    9.261399] [<ffffff80086e9e00>] platform_device_del+0x30/0xa0
[    9.261403] [<ffffff8008810bdc>] dwc3_otg_work+0x204/0x488
[    9.261407] [<ffffff80088133fc>] event_work+0x304/0x5b8
[    9.261414] [<ffffff80080e31b0>] process_one_work+0x148/0x490
[    9.261417] [<ffffff80080e3548>] worker_thread+0x50/0x4a0
[    9.261421] [<ffffff80080e9ea0>] kthread+0xe8/0x100
[    9.261427] [<ffffff8008083680>] ret_from_fork+0x10/0x50

The problem can occur if xhci_plat_remove() is called shortly after
xhci_plat_probe(). While xhci_free_virt_devices_depth_first been
called before the device has been setup and get real_port initialized.
The problem occurred on Hikey960 and was reproduced by Guenter Roeck
on Kevin with chromeos-4.4.

Cc: Guenter Roeck <groeck@...gle.com>
Signed-off-by: Fan Ning <fanning4@...ilicon.com>
Signed-off-by: Li Rui <lirui39@...ilicon.com>
Signed-off-by: yangdi <yangdi10@...ilicon.com>
Signed-off-by: Yu Chen <chenyu56@...wei.com>


---
 drivers/usb/host/xhci-mem.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 2a82c927ded2..295789d993b0 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -947,6 +947,11 @@ void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id)
 	if (!vdev)
 		return;
 
+	if (WARN_ON(!vdev->real_port)) {
+		xhci_warn(xhci, "Bad vdev->real_port\n");
+		goto out;
+	}
+
 	tt_list_head = &(xhci->rh_bw[vdev->real_port - 1].tts);
 	list_for_each_entry_safe(tt_info, next, tt_list_head, tt_list) {
 		/* is this a hub device that added a tt_info to the tts list */
@@ -960,6 +965,7 @@ void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id)
 			}
 		}
 	}
+out:
 	/* we are now at a leaf device */
 	xhci_free_virt_device(xhci, slot_id);
 }
-- 
2.15.0-rc2